ethell



(Model.)

J. J. ETHELL.

MILLSTONE.

N0. 285,118. Patent-ad Sept. 18, 1883.

UNITED STATES PATENT OFFICE JOHN J.ETHELL, OB ST. LOUIS, MISSOURI.

MILLSTONE.

SPECIFICATION forming part of Letters Patent N0. 285,118, dated September 18, 1853.

Applicntion filed May 11. 18E3 (Model.)

T0 all whom 2125 may concern:

Be it known that I, JOHN J. ETHELL, of St. Louis, Missouri, have made a new and useful Improvement in Millstones, 0f which the following is a full, elear, and ex2tct description, reference being had to the annexed drawings, 1 naking part of this specification, in Whlch Figure 1 is a faee view of a millstone having the improvement; F1'g. 2, a section on the line 2 2 of Fig. l, and Fig. 3 a section 011 the line 3 3 of Fig. l. Fig. 4 is a section through Fig. 1 in the plane indicated by dotted lines y y- The same letters of referenee denote the same parts.

This invention relates to millstone-clress; ancl it consists in a new and improved dress, Whi0h Will be 'fully understoocl from the description, when taken in connection witl1 the annexed drawings.

The working-surface 0f the 'stone is slightly concave, anti centrally tl1rough the stone is the eye A. Surrounding the eye are radial .furrows B, which are equiclistant ancl concentric to the axis 0f the stone. These furrows are the shallovest 0f all the furrows 011 the facel 0f the stone, and they have aeute edges b, especially designed for crushing the wheat or other grains preparatory to the grinding process. Surrounding the furrows B is another series 0f furrows, O, wl1ich at their inner ends are one-half as wide as the outer ends of the furrows B, and deeper. In otl1er words, the

furrows B, and tl1ey have acute edges c,-whieh radiat-e fron1 the center of the stone. Like the furrows B, the furrows O are planes inclining from the angles 01 edges c, as shown in Fig. 4. The last series 0f furrows, D, is tangent t0 a cirole described within the circumferenee f the stone, and they are deeper than the two inner series of furrows. These furrows D perf01n1 the grincling operation, 2L11(1 they have aeute eclges d. They are continuous with the furrows B ancl o ne-half the number of flllfS C, as sl1own in Fig. l, forming obtuse .angles at the junctions With the furrows O. This skirt Series 0f furrows incline downward from the lands 01' grinding-faces E, as shown in Fig. l, which faces are all in the same plane. The

series 0f furrows O number just double the furrows are deepei* than the furrows B, as well as series O.

Having describecl my inventi 0111, what I claim seribed.

JOHN J ETHELL'. Witnesse'sr G. D. M001)Y, T110s. L. J ONES. 

